Improvement in casting stamping-heads



I. NV. GATES, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN CASTING STAM PlNG-HEADS.

Specification forming part of Letters Patent No. 29,372?, dated July 31,16604 iication, in which- Figure l represents a vertical central sectionof the flask and center piece put together ready for casting thestamp-head; Fig. 2, a similar section through the center piece detachedfrom the flask; Fig. 3, a similar section, and Fig. 4 a plan of thestamp-head when cast onto the center piece; Fig. 5, a vertical centralsection of the flask and center piece ready for the casting of the die;Fig.

,6, a horizontal and Fig. 7 a vertical section of the die when cast ontothe center.

Similar letters of' reference in each of the several figures indicatecorresponding parts. The nature of my invention consists in the use of ahollow central chill, in combination with an external chilled Ametalflask, in the manner substantially as hereinafter described, so that themetal which, with the central chill, forms the stamp head or die may becast in and around the central chill and against the interior surface ofthe external chilled flask. The object of this process is to chill themetal of the stamp head and die all through, and thus increase theirdurability. Stamp heads and dies as manufactured at present are chilledto a thickness of from onequarter to an inch only. XVhen this thicknessis worn off the rest is very readily used up.

To enable others skilled in the art to make and use my invention, I willproceed to dcscribe its construction and operation.

I rst cast the hollow stem B of the stamphead, the lower part, Bl B3, inan iron flask, and the upper part, B B2, in a second mold, so as tochill the lower part ofthe stem, (which is to form part of the head,)and to have the upper part, or what may be properly called the stem, ofthe stamp-head soit, so that it can readily be turned. The stem, whenfinished, is placed in an iron flask, D D, as represented in Fig. 1, sothat its chilled lower portion forms a center piece of the hollow spaceof the fiask. The molten metal is then poured through the hollow steminto the fiask so as to fill the hollow space in the fiask and stem, asrepresented at A A A, Fig. 3. The stem is originally cast with recessesw on its inner and recesses y on its outer surface, which are afterwardfilled up by the metal A A A, so that when the bottom part of thelstamp-head becomes worn off', and only aring, A A, is left around and acore, A, in the stem, this ring and core will yet be firmly connectedwith the stein and t for use. As the metal is cast through and aroundthe stem, (in the above-described mannen) it is not only chilled fromthe outside in consequence of its contact with the inner surface offlask D D', but also from the inside in consequence of its Contact therewith the center' piece formed by the lower end of the stem. Thus themetal will be chilled throughout, and will thereby be made far moredurable than what the usual stamp-heads are.

I found it necessary to cast the metal through and around a hollowcenter piece, because on casting it around a solid stem it wouldinvariably crack. On pouring the molten metal through the hollow centerpiece it heats and expands and can afterward contract together with thecast head so as to prevent its cracking. The die (Z is cast in a similarVmanner around and through a ring-like center piece, b, which isfastened in the flask c a by pins c. The center piece, b, is made ofchilled cast-iron and provided with recesses similar to the recesses .ty above described. In this manner the die is also chilled throughoutfrom the center as well as from the outside, and is thus made to possessa high degree of durability.

That claim as my invention, and desire to secure by Letters Patent, is-

The use ofa hollow central chill, in combi nation with an externalchilled metal fiask, in the manner substantially as and for the purposesherein described.

The above specification of my improved mode of casting chilledstamping-heads, che., signed by me this 30th day of April, 1860.

I?. XV. GATES.

Vitnesses:

A. D. STURTEVANT, ALvIN SALIsBURY.

